Most Operating Systems (Mac and Windows) and mobile computing devices have built-in tools for screenshots and screen capture. Common features include ability to select partial windows, or the entire screen. Other nice features often include timed screen capture, which affords a delayed screen shot, so the user can make clicks and prepare in advance. Below is a list of additional links for screen capture tools
How to take a screenshot on many different platforms: https://www.take-a-screenshot.org
Here is a link to a good run down of both free and paid mobile scanning apps. Popular options are Microsoft Office Lens, Evernote Scannable, and Adobe Scan. An app like this can be very handy for students who may be doing written homework problems or any work on paper, and then need to quickly and easily convert it to a digital document for submission to Canvas LMS or sharing with team members.